Wasp Archery actually has a nice article on this in the blog section of their website
http://www.wasparchery.com/blog/deer-shot-placement
I'm not sure where people come up with the void thing, because none of the diagrams of deer anatomy I've ever seen show any space between lungs and spine. Its not totally related, but the other cool diagram I've seen is an interactive anatomy diagram that I think can help new hunters identify their shot and maybe get better at finding their deer
http://www.realtree.com/deer-hunting...cement-on-deer